Earth and Science Research (ESR) has a world-wide simulation of Ocean Surface Currents in
Real-Time (OSCAR) which has been running since 1992. They
have been modifying and testing the model for many years and are currently funded by
NASA (previously funded by NOAA).
For people with low-band width internet access, like sailboats,
accessing and using their on-line data
is not easy.

I setup a set of tools to convert their daily simulated results
into a format called GRIB which can be viewed by many weather
tools such as ViewFax
(windows only, but runs under WINE on Linux). Older versions of ViewFax might not show any data -- upgrade to at least Version 5.0.56. To access this data I setup
a email responder just like saildocs.

OSCAR data covers much of the world from 80N to 80S,
spanning the globe from 180W to 180E. The resolution is in 1/3 degree increments.
The time-frame is a 5 day resolution.

Once a day, usually at midnight Pacific Standard Time, the Seattle
office updates their simulation of ocean surface currents. This
snapshot represents their best estimation of what the ocean surface current is
doing. They use a number of techniques and data sources for estimating ocean
current flow. If you would like to see how their model compares to real
data try reading Validation
and Error Analysis of OSCAR Sea­surface Currents written in 2006.

How to Get the Data

You can retrieve the data by email using the following steps. Remember these are ocean currents,
so the model does not extend to the shore line and are more accurate for the open ocean.

The globe is split up into grids with lines running North-South and East-West.
To define a box on the earth's surface specify your latitude in degrees, say 20N and 10N.
Then limit the east-west sides of the box with your latitude, for example 120W to 110W.

Use these corners to fill in the OSCAR command: oscar:lat1,lat2,lon1,lon2. In this example
the command becomes:

You will receive an email response with information about the GRIB file including it's origin.
The attachment will contain the grib file for your requested area.

OSCAR (Ocean Surface Current Analysis Real-time) contains near-surface ocean current estimates, derived using various satellites and in situ instruments.
Data are on a 1/3 degree grid with a 5 day resolution. OSCAR is generated by Earth Space Research (ESR). For project details see http://www.esr.org/oscar_index.html
All data is generated by computer models subject to error. Use data at your own risk. To view this data online see http://www.oscar.noaa.gov
Data extracted from oscar_vel7423.nc.gz last updated 2013-2-06 00:03

With Airmail's email program for HF radios, you can just click on the attachment and ViewFax (version 5.0.56 or newer) will
start and display the data. Otherwise, save the attachment and open your GRIB viewer. In your viewer
you'll need to open the saved attachment "OSCAR-xxxxxxxx.grb" file to view it.

You can mouse over the current arrows in ViewFax to get direction and speed.

Additional Resources

There are not many current models to compare. However NOAA
has an Atlantic Model that can be fetched from "query (at) saildocs.com"
NOTE this is not svsarana.com! Use the command "rtofs:lat1,lat2,lon1,lon2"

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